Here is a picture of a microwave beam generator a friend built in the 1980's. This kind of thing is quite dangerous from both the high voltage and RF level standpoints. There was a special demo, at a computer security conference in Dallas TX, where it crashed a desktop computer from across the room in front of a small audience, and there was a web page for that event, but it's been gone for some 8 or 9 years. There is no schematic or other details but since the pictures show no cover plates on the thing, called the "Hootennanny MK II", it would be almost obvious what was done by anyone qualified to even try it. http://www.montagar.com/~patj/uwdew.htm I would comment that tuning the waveguide stub, with a piston made of bent metal, was a very interesting procedure as it was done with the rig hot by directing the energy toward a bank of flourescent lamps as a tuning indicator and a few sparks did fly from the back of the stub. Don't do this kind of project for a science project, really soneone will probably get hurt even with the best intentions; people like to touch things and flip switches they know nothing about.